ProJax is a collectible jacks variant. Through a combination of card play and traditional jacks action, players attempt to be the first to collect their own five jacks from the playing area. There are three ProJax products so far:Starter Set - Contains 5 ProJax, ProJax ball, 3 Powerplay cards, 10 ID bands, and instructionsBooster Set - Contains 5 ProJax, 2 Powerplay cards, and 10 ID bandsBattle Arena Set - Contains 10 ProJax, 2 ProJax mines, 6 PowerPlay cards, 20 ID bands, 1 ProJax ball, a fold-out cloth arena, and a travel carrier that hold 5 ProJax and a ball. - BoardGameGeek